Precise linear fastener system and method for use

ABSTRACT

The present invention provides a linear fastening system capable of rapid engagement and disengagement. More specifically, the system utilizes a cooperating collet member and a compression ring member which are constructed and arranged to slip easily over a shank member. The fastener system is secured by linearly traversing a compression member in an overlapping fashion over the collet member thereby utilizing ribbed surfaces to compress the collet member to grip the outer surface of the shank member. In this manner, the linear fastener system is capable of providing a precise, secure, and reproducible connection between multiple components without the need to apply rotational torque to the assembly.

REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.10/618,689, filed Jul. 9, 2003 now U.S. Pat. No. 7,658,582, thedisclosure of which is incorporated herein by reference in its entirety.This application is related to U.S. patent application Ser. No.10/358,427, filed Apr. 3, 2003 (now U.S. Pat. No. 7,105,029), thedisclosure of which is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to fasteners capable of rapid linearengagement and disengagement. More specifically, the system utilizes acombination of interlocking sleeve members which combine to form aversatile and effective fastener system which may be used to connectcomponents together without placing torque on the assembly.

BACKGROUND OF THE INVENTION

In general, a fastener is any device used to connect or join two or morecomponents to create an assembly. In the field of manufacturing thereare numerous assembly processes requiring individual components to bejoined with fasteners to create an assembled product. Most of theseprocesses, requiring fixations of one component in relation to anotherare currently performed using threaded fasteners for connections. Themost common threaded fasteners are referred to by many names, amongthem: bolts, screws, nuts, studs, lag screws, and set screws.

Since the invention of the threaded fastener, and particularly the boltand nut combination, various attempts aimed at improving the efficiencyof assembling components with threaded fasteners have been made. Forthis reason, today's product designer has an extraordinary array ofchoices and possible permutations of known fastening concepts andfeatures. Literally hundreds of types and variations of threadedfasteners are available. Because threaded fastener connections oftenhave a significant impact on assembly cost and product reliability, agreat deal of design effort is directed to more efficient designs.Fastener design effort typically involves compromises amongconsiderations such as cost, size, reliability, performance, ease ofmanufacture, and retrofit capability to existing product designs. Whilesome of these designs improve assembly efficiency, they often result inextremely complex, specialized and expensive fastening components.

In addition to the assembly costs associated with threaded fasteners,the rotational torque required for proper utilization of threadedfasteners is often undesired. When a bolt is used to clamp two parts,the force exerted between the parts is the clamping load. The clampingload is created by exerting a tightening torque on the nut or the headof the screw. These forces keep the threads of the mating parts inintimate contact and decrease the probability of the fastener looseningin service. These forces may damage delicate assemblies, such aselectronics and the like. Lock washers, plastic inserts in the nut orbolt, adhesives, cotter pins, locking tabs, etc. are often used toreduce the torque required to prevent a nut and bolt combination frombecoming loose during operation. While these devices are generallyeffective, they add cost and complexity to the assembly operationespecially where automated equipment is utilized.

Accordingly, what is lacking in the prior art is a cost effectivefastening system capable of linear engagement. The fastener systemshould achieve objectives such as providing improved manufacturing andassembly efficiency, effective reliable performance, corrosionresistance, and torque-less assembly. The system should includepackaging flexibility for installation on various products includingretrofitting existing product configurations with minimal modificationof the original product.

DESCRIPTION OF THE PRIOR ART

A number of prior art threaded fastening systems exist for attachingcomponents together to form an assembly. Most of the systems, forexample bolts and nuts, utilize a combination of internally andexternally threaded components to achieve the clamping forces necessaryto create the desired assemblies.

It is also known in the prior art to provide various fasteners capableof partial linear and partial rotational engagement. These fastenersgenerally feature radially inwardly or outwardly biased arcuate segmentsmounted to engage the threads of a bolt, nut or other threaded member.The threaded segments are generally movably mounted within a casing oraround a shaft and resiliently urged inwardly or outwardly. Typicallythe devices are provided with axially spaced apart radially inwardlydirected surfaces of revolution, such as frustoconical surfaces,extending at a common acute angle to the axis of the fastener. In thismanner the fasteners and couplings may be secured by merely pushing thethreaded components together, thereafter final tightening isaccomplished by rotation of the fasteners.

U.S. Pat. No. 5,788,443 to Cabahug discloses a male coupling devicefeaturing movably mounted threaded members which are capable of rapidengagement and disengagement with respect to the stationary threads of afemale coupling device. The male coupling device includes a handledshaft having a plurality of threaded segments surrounding the shaft, asleeve is mounted to move relative to the handle to move the threadedsegments inwardly and outwardly to effectively vary the diameter of theassembled threaded elements.

U.S. Pat. No. 5,613,816 to Cabahug discloses an apparatus for rapidlyengaging and disengaging threaded coupling members. The complex deviceincludes pin assemblies moveably fitted within adjacent V-shapedsegments of the movably mounted externally threaded elements. The deviceis constructed such that as the coupling members are moved relative toone another the pin assemblies force the threaded elements apart. Inaddition, ball assemblies are required to maintain proper alignment andlocking action of the threaded segments, further adding to thecomplexity of the device.

U.S. Pat. No. 5,800,108 to Cabahug discloses apparatus for rapidlyengaging and disengaging threaded coupling members, which eliminates theball assemblies of his prior disclosure. The device includes an outerbody with a plurality of pull/lock/torque pins extending inwardly tocooperate with oval indentations and apertures extending along the sideof the threaded segments. When the sleeve associated with the outer bodyis moved down, the pins abut the oval indentations to lock the threadedelements in place. As the sleeve is pulled upwardly the pull/lock/torquepins clear a ledge formed on the threaded segments allowing them tomove. Continued pulling back of the sleeve allows the pins to passthrough apertures and causes the threaded segments to engage a ramp todirect the segments back and away from the bolt member. The constructionrequires extremely tight machining tolerances to prevent the pins fromdeflecting to the side and preventing operation of the device. Inaddition, the amount of torque which can be applied to the threadedsegments is limited to that which the pins and the oval indentations canwithstand, limiting the device to light duty applications.

U.S. Pat. No. 4,378,187 to Fullerton discloses a quick acting nutassembly. The device consists of a multi-part nut casing having aninclined interior surface adapted for sliding engagement with a threadedjam nut which wedges therein. As the jam nut moves in a first directionalong the inclined surface, it compresses radially and the threads ofthe jam nut engage the threads of the bolt. As the jam nut moves in asecond direction along the inclined surface, it may expand radially anddisengage from the bolt. When the jam nut is in the engaged position itmay be tightened by conventional rotational motion. As the device istightened the threaded segments increase pressure against the fastenermaking the task of torquing the fastener to a specified torquedifficult. In addition, due to the size of the device, it requiresadditional space for wrench clearance and the like.

U.S. Pat. Nos. 5,324,150 and 5,427,488 to Fullerton disclose threadedfasteners having a casing that enclose at least three inwardly biasedarcuate segments positioned to engage the threads of a bolt. The casingdefines spaced apart frustoconical surfaces directed toward the fastenerand positioned to engage corresponding surfaces of the segments when thefastener is turned in a first direction. The casing is also providedwith a second frustoconical surface for urging the threaded arcuatesegments away from the bolt when the fastener is turned in a seconddirection.

While the prior art devices allow partials linear engagement theyrequire rotational torque to produce the clamping forces required tomaintain assemblies. These devices also require extensive machining ofthin sections and require difficult assembly processes for manufacture.This combination results in high production cost and weak finishedcomponents. Still further, it is well known in the art that cold formingmanufacturing techniques result in much stronger and more reliablefasteners. The designs of the prior art devices do not lend themselvesto traditional fastener manufacturing techniques, e.g. cold forming,thread rollers, pointers, nut tappers, slotters, shavers etc., adding tothe high manufacturing cost and reducing the strength of the fasteners.The present invention teaches a linear fastener system that includes aninner collet member and an outer compressing member that is capable ofrapid linear actuated engagement and/or disengagement. In addition, thepresent invention teaches a linear engaging fastener that is capable ofapplying precise clamping force to the assembled components withoutrotating the fastening members. Still further the present inventionteaches a fastener system that lends itself to multiple manufacturingtechniques.

SUMMARY OF THE INVENTION

The present invention provides a linear fastening system capable ofrapid linear engagement and disengagement. More specifically, the systemutilizes a interlocking collet member and a compression ring memberwhich are constructed and arranged to slip easily over a shank memberwhile in a first release position. The collet member is constructed andarranged with an inner engaging surface and an outer ribbed compressionsurface, the compression ring member being constructed and arranged withan inner ribbed compression surface preferably conjugate in shape withrespect to the outer surface of the collet member. The fastener systemis secured by sliding the compression member in a linear overlappingfashion over the collet member, thereby utilizing the ribbed surfaces tocompress the collet member and place a tensile load on the compressionring to grip the outer surface of the shank member. In this manner, thelinear fastener system is capable of providing a precise, secure, andreproducible connection between multiple components without the need toapply rotational torque to the assembly. The connection also allows fullthread engagement and a locking connection without the need for plasticinserts or adhesives. When compared to traditional threaded fasteners,the dual ribbed compression surfaces allow very precise tensile loads tobe applied to the shank member. Prior art designs require torquewrenches to apply measured clamping loads to fasteners. Linearcompression of the collet member eliminates variations as seen in theprior art due to surface finish, lubrication and thread engagement toachieve a precise clamping load.

Accordingly, it is an objective of the present invention to provide afastener system capable of precisely and reproducibly securing multiplecomponents into a single assembly without the need to apply-torque tothe assembly.

An additional objective of the present invention is to provide afastener system capable of precise and reproducible linear engagementand disengagement.

It is a further objective of the present invention to provide a fastenersystem capable of providing precise and reproducible linear engagementto externally threaded surfaces and the like.

A still further objective of the present invention is to provide afastener system capable of providing precise and reproducible linearengagement to snap ring grooves and the like.

Another objective of the present invention is to provide a fastenersystem capable of providing precise and reproducible linear clampingforces to a shank member.

Yet another objective of the present invention is to provide a fastenersystem suited for automated manufacturing and assembly.

Still yet another objective of the present invention is to provide afastener system that allows close spacing and does not require wrenchclearances.

Other objects and advantages of this invention will become apparent fromthe following description taken in conjunction with the accompanyingdrawings wherein are set forth, by way of illustration and example,certain embodiments of this invention. The drawings constitute a part ofthis specification and include exemplary embodiments of the presentinvention and illustrate various objects and features thereof.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows a perspective view of one embodiment of the instantinvention being utilized to secure an automotive valve cover;

FIG. 2 shows a section view of one embodiment of the instant inventionillustrating the collet member with the compression ring in the firstrelease position;

FIG. 3 shows a section view of the embodiment illustrated in FIG. 2wherein the compression ring is moved into the second engaged position;

FIG. 4 shows a perspective view of one embodiment of the collet memberof this invention;

FIG. 5 shows a perspective view of one embodiment of the collet memberof this invention;

FIG. 6 shows a perspective view of one embodiment of the collet memberof this invention;

FIG. 7 shows a perspective view of one embodiment of the compressionring of this invention;

FIG. 8 shows a perspective view of one embodiment of the compressionring of this invention;

FIG. 9 shows a perspective view of one embodiment of the compressionring of this invention;

FIG. 10 shows a perspective view of one embodiment of the shank memberof this invention;

FIG. 11 shows a perspective view of one embodiment of the shank memberof this invention;

FIG. 12 shows a perspective view of one embodiment of the shank memberof this invention;

FIG. 13 shows linear coupling assembly of the instant invention.

FIG. 14 shows linear coupling assembly of the instant invention;

FIG. 15 shows a side view partially in, section illustrating oneembodiment of the present invention in cooperation with a snap ringgroove;

FIG. 16 shows a side view partially in section illustrating oneembodiment of the present invention in cooperation with a generallysmooth shank surface;

FIG. 17 shows a side view partially in section illustrating oneembodiment of the present invention in cooperation with a knurled shanksurface;

FIG. 18 shows a side view partially in section illustrating oneembodiment of the present invention in cooperation with a threaded shanksurface;

FIG. 19 shows an implement for applying linear compression;

FIG. 20 shows a perspective exploded view of an alternative embodimentof the present invention;

FIG. 21 shows a section view of the embodiment shown in FIG. 18illustrating the linear fastener in the first release position; and

FIG. 22 shows a section view of the embodiment shown in FIG. 18illustrating the linear fastener in the second engaged position.

DETAILED DESCRIPTION OF THE INVENTION

Although the invention is described in terms of a preferred specificembodiment, it will be readily apparent to those skilled in this artthat various modifications, rearrangements and substitutions can be madewithout departing from the spirit of the invention. The scope of theinvention is defined by the claims appended hereto.

The linear engaging fasteners 10 utilized to secure the automotive valvecover 14, shown in FIG. 1, are a representation of the general utilityof the present invention. Referring to FIGS. 2 and 3, the linearfastener generally includes an axially aligned collet member 11 and acompression ring member 12 which are constructed and arranged tocooperate with a shank member 13. The external surface 18 of colletmember 11 is constructed generally cylindrical with at least one andpreferably three outwardly and circumferentially extending rib(s) 34positioned about a central axis. Each rib 34 being constructed with afirst ramp surface 36 to allow the compression ring to slide onto therib and a second, ramp surface 38 to allow the compression ring to beremoved from the collet member 11. The internal gripping surface 31 ofcollet member 11 is generally constructed and arranged to have aconjugate surface to the gripping surface 15 of the shank member 13 forcooperative engagement therebetween. The collet member 11 may alsoinclude a flared base 19 suitable to distribute clamping force over awide area or provide a bearing surface for relative rotation of adjacentcomponents. The collet member may be constructed of materials well knownin the art which may include but should not be limited to steel, bronze,brass, copper, aluminum, plastic, ceramic, or rubber, as well assuitable combinations thereof. The compression ring 12, has a generallycylindrical interior surface 20 with at least one inwardly andcircumferentially extending rib 40 arranged around a central axis tocooperate and coaxially align with the outwardly extending rib(s) 34 ofthe collet member 11. Each compression ring rib 40 being constructedwith a first ramp surface 42 to allow the compression ring(s) to slideonto a respective collet rib and a second ramp surface 44 to allow thecompression ring to be removed from a collet member 11. The compressionring 12 may be constructed with a flange 21 about the upper surface. Theflange 21 may have optional lugs 22 (FIG. 8) formed in a C-shape forengaging an extractor (not shown) used to remove or disconnect thecoupling. The flange may also have optional wrench flats 23 (FIG. 9) forengaging wrenches and/or sockets that are well known in the art.

The shank member 13 is generally illustrated in FIGS. 10 through 12. Theshank member includes an outer gripping surface 15 which is preferablyround in shape, but may be oval, hex, d-shaped, square, rectangular orhave other shapes well known in the art that are suitable for shankand/or shaft use. The outer gripping surface may also include any numberof surface finishes well known in the art to enhance the gripping actionbetween the shank member and the collet member, including but notlimited to, threads, knurl, rings, snap ring grooves, generally smoothor tapered surface, or suitable combinations thereof, as well as othersurfaces suitable for providing adequate grip to secure an assembly.

The ribbed construction of the outer surface of the collet member andinner surface of the compression ring allow the two components to beinterlocked into a coaxially aligned sub-assembly prior to assembly to ashank member. In operation, the compression ring and collet sub-assembly50 (FIG. 2), is slid or loosely threaded over the external grippingsurface 15 of a shank member 13. As the interlocking sub-assembly 50contacts the components being assembled the wedging action of thethreads forces the collet open until the outer surface of the ribs 34are forced against the inner surface 52 of the compression ring 12. Thisconstruction allows precise clamping forces to be applied to an assemblyas the compression ring 12 is linearly traversed with respect to thecollet member 11 and the interaction between the threads and the innersurface of the: collet member exert a tensile load on the shank member13. The construction also allows full surface engagement between thegripping surface 15 of the shank member 13 and the internal grippingsurface 31 of the collet member 11, and facilitates a locking connectionwithout plastic inserts or adhesive.

FIGS. 13 and 14 show non-limiting alternative methods of securing thelinear fastener 10 to a shank member. In FIG. 13, the collet member 11can be slid or loosely threaded onto the gripping surface 15 of theshank member, illustrated herein having exterior threads. Therelationship between the threads on the shank and the collet areconstructed and arranged to cause a tensile load on the shank memberwhen the collet is compressed. The shank member may also include anoptional tensioning means constructed and arranged to allow apredetermined amount of clamping force to be applied to the componentsor tension applied to the shank member prior to engaging the colletmember with the compression ring member. The optional tensioning meansis illustrated herein in a non-limiting embodiment as an internal bore32 which includes internal threads 28. The internal bore is constructedand arranged to cooperate with a tension rod 25. The tension rodincludes external threads 26 which are threaded into the internalthreads 28 of the shank member. The external threads 26 engage internalthreads 28 of the shank member to apply a predetermined amount ofclamping force to the component(s) 23 prior to engaging the compressionring 12 over the collet member 11. The ribbed inner surface 20 of thecompression ring 12 is frictionally engaged with the ribbed outer wall18 of the collet member 11. The linear compression coupling results fromequal and opposite forces, A and B, shown in FIGS. 13 and 14, beingapplied to the compression ring and the collet member, simultaneously.Once the collet member is collapsed to the shank member the compressionring is tensilely loaded to maintain the compression force, resulting ina connection that is resistant to undesired loosening.

FIG. 13 shows an alternative tension means for applying a predeterminedamount of clamping force to a component, wherein the shank member 13includes a tip 24 constructed and arranged to be grasped by an assemblytool 90 (FIG. 19). Other alternative tension means suitable for graspingthe shaft member to apply a predetermined amount of clamping force tothe components prior to engaging the linear fastener may include butshould not be limited to frangible stems, internal or external grooves,cross drilled apertures, internal bores and flats as well as othersuitable means well known in the art.

In FIGS. 15 through 18, final assembly of the collet member 11 and thecompression ring 12 are shown engaging various outer gripping surfaces15 of shank members 13.

FIG. 19 shows an instrument having a pistol grip 93, a power source 94and concentric pistons 91 and 92. Piston 92 is sized to grip the tensionrod. Piston 91 is sized to seat on the compression ring. As theinstrument 90 applies progressive pressure through concentric pistons 91and 92, the compression ring 12 moves downwardly reducing the diameterof the collet member 11 and tensilely loading the compression ringthrough the interaction of the complementary ribbed surfaces. Theinterior gripping surface of the collet member tightly engages theexternal gripping surface of the shank to provide a lockingrelationship. Once all slack is taken out of the linear coupling, theextension rod may be constructed to break at the limit of optimumpressure. Alternatively, the instrument 90 may have a gauge for settingthe desired pressure wherein the shank member is released aftercompression.

In the event that a linear fastener must be removed, a similarinstrument may be employed. One of the pistons would have a flange withflat lugs. The instrument would be placed over the compression ring andturned to engage the flat lugs and opposite force is applied to removethe compression ring from the collet member. The linear coupling isseparated without placing pressure on the fastened components.

FIGS. 20 through 22 show an alternative embodiment of the presentinvention wherein progressive linear engagement of the compression ringover the collet member applies tension to the shank member as it rampsupwardly on the collet member. In this embodiment the shank memberincludes at least one conical or angled surface 29 which cooperates witha conjugate surface 30 within the collet member 11.

All patents and publications mentioned in this specification areindicative of the levels of those skilled in the art to which theinvention pertains. All patents and publications are herein incorporatedby reference to the same extent as if each individual publication wasspecifically and individually indicated to be incorporated by reference.

It is to be understood that while a certain form of the invention isillustrated, it is not to be limited to the specific form or arrangementherein described and shown. It will be apparent to those skilled in theart that various changes may be made without departing from the scope ofthe invention and the invention is not to be considered limited to whatis shown and described in the specification.

One skilled in the art will readily appreciate that the presentinvention is well adapted to carry out the objectives and obtain theends and advantages mentioned, as well as those inherent therein. Theembodiments, methods, procedures and techniques described herein arepresently representative of the preferred embodiments, are intended tobe exemplary and are not intended as limitations on the scope. Changestherein and other uses will occur to those skilled in the art which areencompassed within the spirit of the invention and are defined by thescope of the appended claims. Although the invention has been describedin connection with specific preferred embodiments, it should beunderstood that the invention as claimed should not be unduly limited tosuch specific embodiments. Indeed, various modifications of thedescribed modes for carrying out the invention which are obvious tothose skilled in the art are intended to be within the scope of thefollowing claims.

What is claimed is:
 1. A precise linear fastener system comprising: acollet member having a base end, a top end, an inner engaging surface,and an outer ribbed surface positioned about a central axis, said outerribbed surface including a first non-helical circumferentially extendingrib spaced apart and in a parallel plane with at least one additionalnon-helical circumferentially extending rib; a compression ring memberhaving a base end, a front end, an inner ribbed surface having a firstnon-helical inwardly extending rib spaced apart and in a parallel planewith at least one additional non-helical radially inwardly extendingrib, and an outer surface positioned about a central axis; said innerribbed surface of said compression ring member being constructed andarranged for coaxial alignment and overlapping engagement with respectto said outer ribbed surface of said collet member, said compressionring member non-rotationally linearly traversable with respect to saidouter ribbed surface of said collet member between a first releaseposition and a second engaged position, wherein said engaged positionresults in said outer ribbed surface of said collet member and saidinner ribbed surface of said compression ring compressing said colletmember and tensilely loading said compression ring member to engage ashank member having an outer gripping surface whereby said collet memberis clamped to the shank member without rotating said collet member, andwherein said release position results in expansion of said collet memberthereby releasing the outer gripping surface of the shank member.
 2. Theprecise linear fastener system of claim 1 wherein said shank memberincludes a first end and a second end.
 3. The precise linear fastenersystem of claim 1 wherein each said outwardly and circumferentiallyextending rib, includes a first ramp surface to facilitate coaxiallyaligned linear overlapping movement of said compression ring in relationto said collet member for engagement thereof.
 4. The precise linearfastener system of claim 1 wherein said inner engaging surface of saidcollet member is constructed and arranged with a conjugate shape inrelation to said outer gripping surface of said shank member.
 5. Theprecise linear fastener system of claim 4 said inner engaging surface ofsaid collet member is conical in shape for cooperation with a conjugatetapered surface on said outer gripping surface of said shank member;wherein linear traversal of said compression ring member with respect tosaid axially aligned collet member-compresses said collet member andtensilely loads said shank member.
 6. The precise linear fastener systemof claim 1 wherein said first end of said shank member includes atensioning means, said tensioning means being constructed and arrangedto allow said shank member to be tensilely loaded prior to lineartraversal of said compression ring member into said engagement positionwith respect to said collet member.
 7. The precise linear fastenersystem of claim 6 wherein said shank member tensioning means includes atleast two generally flat surfaces, wherein said at least two generallyflat surfaces are constructed and arranged for gripping and placing atensile load on said shank member prior to linear traversal of saidcompression ring member into said engagement position with respect tosaid collet member.
 8. The precise linear fastener system of claim 6wherein said shank member tensioning means includes at least one grooveextending around the circumference of said first end of said shankmember, wherein said at least one groove is constructed and arranged forgripping and placing a tensile load on said shank member prior to lineartraversal of said compression ring member into said engagement positionwith respect to said collet member.
 9. The precise linear fastenersystem of claim 6 wherein said shank member tensioning means includes atleast one internal bore extending inwardly from said first end of saidshank member along the longitudinal centerline of said shank member,wherein said at least one internal bore is constructed and arranged forgripping and placing a tensile load on said shank member prior to lineartraversal of said compression ring member into said engagement positionwith respect to said collet member.
 10. The precise linear fastenersystem of claim 9 wherein said internal bore includes internal threads.11. The precise linear fastener system of claim 9 wherein said internalbore includes at least one axially aligned groove extending around thecircumference of said internal bore.
 12. The precise linear fastenersystem of claim 6 wherein said shank member tensioning meats includes afrangible stem, whereby said frangible stem is severed from said firstend of said shank member when said first member reaches a predeterminedtension prior to linear traversal of said compression ring member intosaid engagement position with respect to said collet member.
 13. Theprecise linear fastener system of claim 1 wherein said outer ribbedsurface of said collet member and said inner ribbed surface of saidcompression ring member are constructed and arranged to maintain anaxially aligned interfitting relationship in said release position. 14.The precise linear fastener system of claim 1 wherein said collet memberis constructed from one of plastic, copper, brass, bronze, aluminum,steel, or rubber.